The present invention concerns the production and arrangement of a plurality of edge contoured slats, for use, preferably in blinds, specifically venetian blinds.
Venetian blinds, which have a number of spaced apart horizontal slats hung together with cord, have been known for some time. Recently, the applicants for the present application have suggested making Venetian blinds using slats with edges which have been specifically contoured. The result is a new aesthetic visual effect in the finished blinds. The present invention is intended for use in the production of such slats for such blinds.
Some visual effects can be achieved by using identical slats throughout. Other effects require slats with similar edge contours but with the contouring phase--shifted from one slat to the next. Others again require slats with random edge contouring. In many cases it is not sufficient that the slats should differ from each other. They must differ in precise ways and must be stacked in a correct order.
Patent document EP-A-0 378 313 describes a method and apparatus for cutting a strip material into slats for venetian blinds. The strip material from which the slats are cut is pre-printed with a surface pattern. This document indicates how to prevent the production of a blind with adjacent slats having specific portions of surface pattern at the same distance along their lengths.
It is an aim of the present invention to provide sequences of slats with edge contours, arranged according to a required edge contour pattern.
The inventors of the present application have determined that one problem with using contoured slats is that the contours can interfere with any lift cord holes, ladder guide notches, and even the ends of the slats both visually and physically, such that the blinds may not work efficiently or may be in danger of failing.
It is a further aim of the present invention to remove, or at least partially alleviate, the problems of such interference.